Fluid pressure brake



March 20, 1945. B. H. BRowALL FLUID PRESSURE BRAKE Filed Feb. 6, 1943 2Sheets-Sheet 1 1 mi y A March 2,0, 19P45.` Q H BROWALL 2,371,798

FLUID PRESSURE BRAKE Filed Feb. 6, 1943 2 Sheets- Sheet 2v v H. .RoWALLPatented Mar. 20, 1945r FLUID massima. BRAKE` Bert Henryv Browall,Malmo, Sweden, assignor to Svenska Aktebolaget Bromsregulator, Malmo, ySweden, a corporation of` Sweden l `f Application February 6,1943,serial No. 475,017

l v In Sweden November 27,1940

y 1o claims.` (criss- 195) j This application is a continuation-impartof my U. S. `patent application Serial No. 424,535 led December 26,1941.

' This invention relates to fluid pressure brakes for vehicles,especially railway vehicles, and more particularly to brakes comprisingavariable leverage brake rigging that can be set for one or the other oftwo different brake applying leverages by means of a, leverage switchingmechal nism preferably in the form of a so called brake Fig. 4`isadetail section through a portion of the brake valve equipment shown inFig. 3 and -illustrates one form of connection of the pressure uidsupply Aconduitior the servomotor to `the brake valve equipment. Y

Fig. 5`is also a somewhat diagrammatical view illustrating, partly inelevation and partly in section; one suitablev form ofA arrangement ofthe rod coupler which may be for instance of the type disclosed in U. S.PatentA No. 2,081,660, issued to Axel Georg Hjalrnar Carlbom, or No.2,081,672,

issued to Nils Gunnar August Malmquist, both'on May 25, 1937.

One object of the invention is to provide means for performing thesetting of the leverage switching mechanism or brake rod couplerautomatically under the control ofthe load of the ve`l hicle.

Another object o f the invention is to combine the brake rod couplerwith a pressure fluid operated servomotor for performing the setting ofthe variable leverage brake rigging for the` lower or the higher brakeapplying leverage auto.'

matically under the control of the vehicle load.

For these and further objects, which- Willgbecome apparent from thefollowing description, the invention consists in the arrangement and inthe combination', construction and organization of parts hereinafterdescribed and illustrated by way of examples in the accompanyingdrawings vand finally pointed out in the appendant claims.

In the drawings: i l j Fig. 1 is a fragmental plan view of a variableleverage brake rigging and illustrates, by way of example, a well `knownleverage switching mech'- anism or brake rod coupler for setting thebrake rigging for one or the other of two different brake applyingleverages.V

l Fig. 2 is across section on a larger scale of thebrake rod couplershown inFig. 1 and illuserating pressure fluidirom the pressure iluidfbrake valve equipment and under the control of a valve device operableby means responsive to,"

the load of the vehicle. v

controlvalve device and the load responsive meansforoperating it at arailway bogie or truck.

Referringrst to Fig. 1, this shows a conventional brake riggingcomprising a iluid pressure n brake cylinder I and associated `cylinderlever 2 and floating lever 3, which are connected to the brake levers ateach en d oi the vehicle (not shown) by means of pull rods 20I `and 30|.One of these pull rods may suitably be provided with an automatic slackadjuster 202, for instance of the type described in my U. S. Patent No.2,225,001,

' issued on December 17, 1940. Reference number 302 denotes theoperating rod for such slack adjusted. Levers 2 and 3 are interconnectedby means of two rods, the so calledempty rod 4 and the so called loadrod 5,*which serve the purpose of supporting levers 2 and 3 in differentpoints determining a lower and a higher brake applying leverage,restpectivelylf The higher .brake applying leverage is obtained `bymaking vthe empty rod 4 inoperative, so that the braking operation is`carried out through the load rod 5. yThe empty rod 4 is made operativeor inoperative by means of a leverage switching mechanism or rod on anarm I0 pivoted on a shaft Illparallel to the-rod 4. so that the abutmentblock`9 can be y moved to and from the rodextension 4a transverselythereto. The abutment block 9 is adapted for coaction with anabutmentI2, Fig. 1, on`

the projecting end of"` the rod extension 4a. Preferably this abutmentI2 is in the form of a nut adjustably screwed onto the projecting end ofthe rod extension 4a.., lWhen in the active position shown in Fig. 2 theabutment block 9 lies inthe path of movement of the abutment nut I2 onthe extension 4a`of the rod 4 and thereby reduces the lost motion of thelatter in relation to fluid operated servomotor for moving the abut-2ment block 9 from the active positioninto the inactive position and forholding the Aflbuiieit block in this last mentioned 'position gainst'-`Vthe action of a spring I3 ortheli-ke.` `T motor comprises a cylinder I4preferably mte ebeiment moeke-,1 .Ai-.fthe end-,Opposite tothe.pee-.ieetirre 'pister-wed. I6.. the. .er1-inemA l 4 -israref vided-with;Lein inletv en@ elitlei Greenies- .il-l ...ier the eeeeti-ee pressurefluid-i shew-r1 in 1 this-opening Il is connetedgby means 0xff-afleX-ible pipe er1-.lese |8119 e pipe eenden J9 which extends 'teexee1"-.r1sr.e.f 'the pressure uid brake valve equipment, which isimmediately setdunderr miie `p17-'essuie .i ene epplieeiiee O fi the;"brekeut inem, vi'fhieh.A the eid pressurezelieeppearemhen the brakeisreleased. lThen-flexible pipevor hose lfisefreneed 1:0 allew'ferrlevemeni @fthe serve: meter e'ylieder. |54- ieeeiherw-ththe-,housing 6 and the leven in relation to the xedly mountedpieeeendeii Iii..L Y Y.

The piston Iearries en its upper end acircilar "dg'e 'I5`I `vvhic`h,wlfie'n 'operating pressure spi-ing I3` er ordinary J circumstances,yinit shrii trie 'abutment 'meer st xb'e prevented from moving, theforce created vby""tlfie operating vpressure on the piston` I5 'wlloverconelfthe tension o'fth'ef'ep'ring 153 fe'riqeu'eh'tlie Diepen .l5uw wards until thefegeh'lfl l'abuts the packingV ring Idil, 'thu-s evenin case producing the desiredsealing. against leakage.

I freight brakel valve equipment ftype AB Vconrprising the -servceandemergency portions-Ztl andy-21|, :respectif/e155..onqeacn side of thepipe v bracket .portieri zz te wnienine r1lei-aire.pipe za. the twocompartment vreservoir y24 and thel brake' eylindelfnet eeewn .ain Rias)ere eemleetedfm ihe ueuelmemief, .the brake evlgieiie'rbv the pipe` Whenthehbrake valvev *edilinn1entl -isof gralV with the housing 6, and a'piston' Iv-5*;whicnjggis .n movable in the cylinder and providedZwithia pis'-4 i, ton rod I6 projecting into the housingj fondi-IV prect actuation of the pivoted arm l caryirigthe so called inshot valve28 in the emergency portion 2I of the brake valve equipment, as shown inFig. 4.

In the conduit I9 there is provided a controly yorig. 4) inside theopening 2s in the emer- .gen-cy portion .2| of the brake valve is ventedto the atmosphere and thereby relieved from the operating device'ier,positively lifting the check Valve-30 from its seat in case the vehicleload exceeds apredetermined value, so that in such case tthe uidpressure immediately building up the `space 3-12- (Fig. 41 at anapplication @of Ithe f brake `will bevtransm-itted Y'thrnighthe conduitthi's typethe conduitls'fpreferably mayfbe con?V neetefi i0 the.'ineeeiiennerenine 2e fenetre:

mei/erlie e plus normally elesinerhetzep'e 11s).-

I9 to the servomotor cylinder ld-andfactuategthe pis-ton lather-ein formoving the l`abutment block @put of the-active .position shownin Figi`2. In the form shown ini-ig. i 3 the Iload responsive operating -devicecomprises a double -armed `flever 33 .pivoted cna supportingspringbracket -34 on theyeliicleriframe Hand-havingone of its-arms cupled byAmeans of -a =link 351 to -an Aaxle Abox A ,31 of the veljii'czle,lthepther armbeing connected to the vehicle `vframe by f-m'ean's -ef adashepot 3831 {Ihe arm connected to theaxle xbfyx is idiA videdintoutwoparts, 4Il articulated in relation to e'ach other in the planeof movement -of the lever 4aruglgiri botlidi-rections against the action10fa 4spr-ing 4I. l'heydeection of -thesup-` porting-spring 42 of thevehicle under the -load thereof, imparts movement-tothe lever w3%) whichis provided with a `projecting arm 43 for the actuationvpf the valve 30.The dashepot $8, owing` to the resilient articulation of -the Ileverair-n1- onnected to -the axle lbox, will :preventor sfnjioothY thetransmission of rock-ing movements between the frehicle tram-e -35 -a,nd rthe' facile box `3"!to the valve actuatingarnfrv 113.v

Fig.: 5 shows La -fqrm1of` arrangement of- `the c ,ontrolr valve devicel29, "30 and fthe load respon sive actuating device thereforatea-railwayfbogie' orqtruck.V In this case 'the,-lever ,33- lisgpivotedto; a bracket '44- fsecured to theispring-supported bogiegbolsterpllrzonwhich also the -housing 29 of the control valve 1is secu-red,-wliereasthe articulated arm of the lever 33 is connected by the` link 3B to thebogie fframeeitl.` i lIihevadwantages iganed `Icy ithe 'arrangementdescribed for iperformi-ng th'e fsettirlfgiof 'the' "brake applying ileverage fswitching imecliani'sm auto-- matioally under the control ofitheevehicle' rload' are tor be found in the simplicity 'offcoristriicti-otn andin `the -relifability of ifunctio'nfand "n that thearrangementsrequirs'a :reiativefly 'small space and 'easily canbeffrnounted in brakes aileV ready-at hand with lthesmallest:possiblechanges thereof.- lA further radvaritagie especial Itov ftheipiee ferredforni` :illustrated:v sin 1%;- according which the :prvessuregfluido'pelated fse'r'vornotor -is directlyy combinedy with-the housing `ofthe? leverage {gswitchi-ng mechanism -or ibrake A4rod coupler. resides-in-the-possibi1ity of constructing andv mounting the rod-couplerandftheservom'otorfa's a.=unit,.andthis-also -in IAsucncases in which rvtheleverage i--switch-ingemeehanism or trod -ebupler is mountedonfakniiovahlebrakefle-ver-so 1as to-r (pare, take in the movements thereof.

Obviously-the invention is` notlimited'fto4 the` l forms hereindescribed and shownontlie drawingsfor the purpose of illustration,sincelimany changes can bel made without-departing from the spirit ofthe invention and thescope @f1-,he` am pendant claims. v

, What I claim and desireto secure ley-.Letters Patent is; t t

1. In a iiuid pressure brake `for vehicles, a variableleverage Vbrakerigging ,including-a brake lever, a rod for supporting saidbrake ,leverata p oint determining a low brake applying` leverage,

means for supporting said lever at another point determining* a highbrake applying leverage, and

a rodl coupler-comprising a housing-pivoted `to said brake lever vat.said first-mentionedrpoint', and a member carried` in said housing andmovable therein into and out of an `active position for setting saidsupporting rod into and out of operation,"a pressure iiuidV operatedservomotor comprising a cylinder carried on said housing and movabletherewith, and a piston in said cylinder for actuating said movablemember, a pressure iiuid supply control valve device for saidservomotor, and means responsive to the load of the vehicle foractuating said control valve device, said servomotor cylinder beingintegral with said housing. t v

2. In a iiuid pressure brake for vehicles, a variable leverage brakerigging including a brake lever, a rod for supporting said brake leverat a point determining a low brake-applying leverage, means forsupporting said lever at another point determining a high brake applyingleverage, and a rod coupler comprising ahousing pivoted to said brakelever `at said first-mentioned point,

and a member carried in said housing and movable therein into and out ofan active position for setting said supporting rod into and out'of operlati-on, a pressure iiuid operated servomotor comprising a cylindercarried on said housing and movable therewith, and a piston in saidcylinder for actuating said movable member, a pressure fluid supplycontrol valve device for said servomotor, and means responsive to theload of theA vehicle for actuating said control valve device, saidservomotor piston being provided with a piston rod projecting into saidhousing for direct actuation of the movable member therein.

3. In a iiuid pressure brake for vehicles, a variable leverage brakerigging including a brake lever, a rod for supporting said brake leverat a point determining a low brake applying leverage, Y

means for supporting said lever at another point determining a highbrake applying leverage, and a rod coupler comprising a housing pivotedto said brake lever at said `first-mentioned point, and a member carriedin said housing and movable therein into and out of anactive positionfor setting said supporting rod into and out of operation, a pressureiiuid operated servomotor comprising a cylinder carried on said housingand level Carryngthe same in; relation to .sa-idA pipe COIlduit.f f l l,i

, housing and movable therein into and'out of an active position forsetting said supporting rod into and out otoperation, apressure fluidoperatedservomotor carried on saidy housing and movable therewith,saidservomotor comprising a cylinder and a piston in said cylinder foractuating saidmovable member, f

l f5'. In an empty and loadlbrake;` equipment `for a vehicle having avariable leverage brake rigging including a brake lever, a rod forsupporting said brake lever at a point determining a lower brakeapplying leverage, means for supporting said brake lever at anotherpoint determining a higher brake applying leverage, and a rod couplercomprising a housing pivoted to said brake lever at said first-mentionedpoint, a servomotor cylinder integral with said housing, and a pressureiiuid operated piston in said cylinder for controlling said rod coupler.t

6. In an empty and load brake equipment vfor a vehicle having a variableleverage brake rigging including a brake lever, a rodfor supporting said`brake lever at a point determining a lower brake applying leverage,means for supporting said brake lever at another point determining ahigher brake applying leverage and a rod coupler comprising a housingpivoted to said brake lever `at said first-mentioned point and a membercarried in said housing and movable therein into and out of an activeposition for setting said supporting rod into and out of operation, a`servomotor -cylinder carried on said housing and movable therewith, apressure fluid operated piston in said adapted for controlling the saidleverage switching mechanism, a pressure fluid supply control valvedevice for said servomotor, and a communication between said controlvalve device and said servomotor, said communication comprising a exibletubing permitting movements `of said servomotor relatively to said-control valve device.

8. In an empty and load brake equipment for a vehicle having a variableleverage brake rigging, a uid pressure system for operating the brakerigging, a constructional unit comprising alever^ age switchingmechanism forming part ofthe variable leverage brake rigging andcomprising means movable into two diierent positions for conditioningthe brake rigging for two different brake applying leverages, and ahousing carrying and encasing said movable means, and a iiuid pressureoperated servomotor for actuating said movablev means, said servomotorcomprising a cylinder carried on said housing, and a piston in saidcylinder, valve means for controlling said i9. :In fan empty fan-d iloadibrakeleqipmentfor I wvehicleihavingravariablefleverageJorakegging, naiuid :Ypressureystem ffor l operating *the iai-'aliek rigging :aconstructionalz unt"cmnprisingfa:lever-'- age ,switchingmechanism'i'forming 1part ff 'the variable :leverage brake rigging andfcompz'isin'g means lmovable into #two l-"cliferentpostions fior-conditioning 'the brake 1 rigging for lStv/o :'diierent brake applying:leverages,= and fahousing. cars-ying and encasing 'l said fmovablemeans, Land a fluid pressurenoperatedsenvomotorffor actuating saidmovable means, :s said' xsenvomotor comprising f a cylinder :rigidly`united :Withxsai'd'I hos'ing, ,and Ix a piston 1 ini said 'rcylindenlvalve. means for fconti'olling said servomotor,andrlm'eansi-aetinginre- .awhicleihavingiaivariableleverage brake-=rigg`ing inclu-dilaga nmnberiof brake '-levers, a "'uifd'- pressure"-system fior yopzverating the 'brake '--igging A-a constructional' unitAcompiisingi a' vleverageswitching mechanism forming part oftheihrakeigging `anni'comprising la housing apivoted *to l'one -of thelin'g sai`cl"servomotor, and 'means'facting sin-'reslzuonselto` theloadlof JKthe vehicle for 4controlling 'said valverl-rneans. n Y

y *LBERTJHENRYBROWALL

